the nervous system, synapses & reflexes

• What do large multicellular organisms like humans rely on for communication between body parts?

  Nervous and endocrine systems
• What are the two organ systems that help coordinate behavior in humans?

  Nervous system and endocrine system
• What are the main topics to know about the nervous system?

  • Structure of a nerve cell
  • Structure of the nervous system
  • How a reflex arc works
• What is another name for a nerve cell?

  Neuron
• How are neurons adapted to carry electrical impulses?

  They are long, thin, and have branches
• What is the function of a synapse?

  To connect two nerve cells
• What happens when an electrical impulse reaches the end of a nerve cell?

  It causes the release of chemicals
• What do the chemicals released at a synapse do?

  They trigger another electrical impulse
• What is the central nervous system made up of?

  Brain and spinal cord
• What role does the central nervous system play?

  It processes sensory information and sends orders
• What do sensory neurons do?

  Carry information from receptors to CNS
• What type of information do sensory neurons carry?

  Information about changes in the environment
• What do motor neurons do?

  Send impulses from CNS to effectors
• What are effectors generally?

  Muscles or glands
• How does the nervous system respond to changes?

  By sorting information and sending responses
• What is a reflex arc?

  • Nerve pathway for unconscious reflexes
  • Example: moving hand from a hot surface
  • Rapid and automatic response
• Why are reflexes beneficial?

  They allow rapid and automatic responses
• What is the role of receptor cells in a reflex arc?

  They detect stimuli like pressure
• What happens after a receptor cell detects a stimulus?

  A sensory neuron carries the impulse to CNS
• What does the relay neuron do in a reflex arc?

  Transfers the impulse to a motor neuron
• What is the final step in a reflex arc?

  The motor neuron sends impulses to effectors
• What happens at synapses in a reflex arc?

  Electrical signals convert to chemical signals
• What is the purpose of the nervous system?

  To detect changes and respond to them